Gene polymorphisms of macrophage migration inhibitory factor affect susceptibility to chronic hepatitis B virus infection in an Iranian cohort.

Macrophage migration inhibitory factor (MIF), a key proinflammatory mediator, plays important roles in chronic diseases. In this study, an attempt was made to clarify the associations between some functional polymorphisms such as MIF-173 G/C, MIF 95 bp and 189 bp insertion/deletion (I/D) polymorphisms and chronic hepatitis B virus (HBV) infection. Polymorphisms were assessed in 221 HBV patients and 200 normal subjects. MIF-173 G/C and MIF 95 bp and 189 bp I/D polymorphisms were genotyped using PCR-RFLP and PCR, respectively. When allele and genotype frequencies of the variants were compared between patients and controls by the χ(2) test, it was found that the frequency of MIF-173 G/C genotypes differed significantly between patients with chronic HBV and healthy controls (P < 0.05). Carriers of the MIF -173-C allele were at significantly higher risk of HBV infection than carriers of the MIF -173-G allele (P = 0.009, OR = 1.549, 95% CI = 1.114 - 2.155). Moreover, 95 bp I/D polymorphism was not associated with CP and the 185 bp I/D variant was not polymorphic in our group of subjects. The frequency of haplotypes did not differ significantly between groups (χ(2)  = 11.391, P = 0.181). Our results suggest that MIF -173 G/C variant increases the risk of HBV in Iranian subjects. Further studies with larger sample sizes and different ethnicities are required to validate our findings.